"You will be very thirsty after so much talking on the phone."

Translation: Vi tre soifos pro tiom da parolado ĉe la telefono.

[bjoholm]

I wrote: "vi estos tre soifa post tiom da telefoni". Why is this incorrect? I am not sure it is correct, so I am hesitant to report.

[jxetkubo]

… post telefoni tiom

or

… post tiom da telefonado

If you use telefoni the object is tiom an you do not need da. I think it would be better to put the object behind the infinitive.

If you want to give the information what you did so much you have to make a noun from the verb. This is normally done by the suffix -ado instead of -i.

[bjoholm]

thanks!

[Amikema]

Isn't 'Vi ege soifos' the same as 'Vi tre soifos'?

[jxetkubo]

More or less, yes, it is. For me ege is a bit stronger than tre because -eg- is normally a suffix and it gets more emphasized when put before the word as an adverb, whereas it is the normal position for tre.